Combination drier and kiln unit



Jan. 7, 1936. R. c. Nx-:wHoUsE COMBINATION DRIER AND KILN UNIT FiledApril 10, 1935 Patented Jan. 7, 17936 VUNITED STATES PATENT OFFICE g2,027,059 COMBINATION ninna AND KILN Unir Application April 10, 1933,Serial No. 665,284

12 Claims.

This .invention relates in general to apparatus for drying and h eattreating materials, and more particularly to rotary kilns of the typeused for drying and burning such wet raw materials as slurry used in theprocess of manufacturing Portland cement or the like.

To increase the effectiveness of rotary kilns in drying wet material,chains or other heat transferring elements have been arranged withinkilns in such manner that when the kiln is rotated the heat transferringlements are alternately plunged into the wet material and lifted out ofit covered-with a coating of the material, thereby exposing a largesurface area of the material to the hot gases passing through the kiln.The heat 'transferring elements also absorb heat from the hot gases andtransfer the heat to the wet material when they are again plunged intoVit.

Chains or likeheat transferring elements used in this manner have beenfound to be highly beneficial and to increase materially the efficiencyof heat utilization of a rotary kiln. However, the chains 'installed inrotary kilns of the usual type have been limited in extent to thatportion of the kiln in which the material being dried is suflicientlywet to cling to and form a coating on the surface of the chainsprotecting them from the destructive action of the hot kiln gases. Also,thetotal amount of chains which limited because if a large amount ofchain is used at the upper or inlet end ofthe kiln the Wet material willbe heated by the upper chains to such extent that itI will dry quicklyon the chains at the lower end of the kiln andl will not adhere to andprotect the lower chains from destruction by the hot gases.

' A general object of this invention is to provide a rotary kiln that ishighly eflicient in recuperating heat from combustion gases in theprocess of drying wet material.

Another objectof the invention is to provide a rotary kiln of the typeutilizing chains or other heat transferring elements in which more thanthe usual amount of heat transferring elements may be utilizedeconomically and with 'increased eflicien'cy.

Another object of the invention is to provide a rotary kiln for dryingand burning wet material in which the portion of the -kiln performingthe drying operation is formed separate from the portion thereofperforming the burning/operation in order that each portion may beoperated lndependently in the most efli'cient manner.

Another object of the invention is to provide may be utilized in a kilnhas been definitely4 meansto prevent destruction by hot kiln gases ofheat transferring elements within a kiln.

Anotherobject of the invention is to provide means for introducing partof the wet material to be dried in a kiln equipped with heat transl- 5ferring elements directly on to the heat transferring elements exposedto the incoming hot kiln gases to protect these elements from thedestructive action of the hot gases.

Another object of the invention is'to provide 10 means for spraying wetmaterial into the discharge end of the drying drum of a kiln and uponthe chains therein to reduce the temperature of the incoming kiln gasesand to provide a protective coating on the chains.

A further object of the invention is to provide. means for maintaining auniform ow of wet material 'to V a kiln and to provide adjustablespraying means for spraying' a selected portion of the uniform 4iiow ofmaterial on to the chains 20 at the discharge 'end of the drying drum ofthe kiln.

According-to the present invention, a rotary kiln apparatus for dryingand burning such material as slurry for making cement is preferably 25divided into two independent parts, a burning drum and a drying drum,although a unitary kiln may be utilized. The drying drum is providedwith chains or other heat transferring elements arranged therein foragitating and transferring heat to the slurry being dried.v Means arearranged to providea uniform flow of slurry to the kiln and means .areprovided for withdrawing a regulatable portion of the material flowingto the kiln and for spraying it into the lower or discharge end of thedrying drum insuch manner that it impinges upon the lower chains of thedrum to form a coating protecting them from being overheated anddestroyed by the incoming hot kiln gases. The spraying apparatus is soar- 40 ranged that any. desired portion of the material supplied to thekiln may,be sprayed upon the lower chains, the remaining material beingfed intothe intake end of thekilnin the usual manner. By this apparatusit possible to utilize suflicient additional chains in the kiln toreduce theD temperature of the combustion gases discharged from thekilnI to 200 F. or lower, whereas the temperature of the combustiongases discharged from kilns of usual construction is ordinarily about400Y or 500 F,

'I'he foregoing and other objects of this invention, will be more fullyapparent upon reading 'the following Dart of this specication inconjunction with the accompanying drawing and may be performed by theparticularfembodiment of the invention shown by way of illustration inthe several views thereof which are as follows:

Figure 1 is a view partly in side elevation and partly in longitudinalsection showing a two part rotary kiln constructed in accordance withthis invention Figure 2 is a View in side elevation partly broken awayon the line II-II of Figure 3 showing the slurry feeder for maintaininga uniform flow of material to the kiln;

Figure 3 is a plan View of the slurry feeder shown with the top removed;and

Figure 4 is a fragmentary showing in side elevation of a unitary kilnconstructed in accord-L ance with this invention.

Referring more particularly to the drawing, the two part rotary kilnshown in Fig. 1 comprises essentially a rotary drying or head drum Iand-arotary burning or -tail drum 2 each so mounted as to be rotatableindependently of the other. The rotary head drum I. is supported upon afloor 3 by means of spaced supporting abutments 4.which carry pairs ofspaced inclined rollers 5 that engage with cooperating riding rings 6 onthe outer surface .of the drum.

.Another support may suitably carry a driving pinion 8 meshing with anexternal gear 9 fixed on the outer surface of the drum I, and wherebythe head drum may be rotated at the proper speed to advance the materialto be dried therein at the proper rate depending upon the inclination atwhich its axis may be directed.

The rotary tail drum 2 may similarly be rotatably supported throughpairs of rollers II mounted on inclined supports III carried by thefloor 3, which rollers rotatably` support the drum 2 through directbearing of external rings I2 fixed4 to the drum 2, on the pairs ofrollers II. Similarly, another support may carry a driving pinion I3which meshes with an external gear I4 fixed on the external surface ofthe drum 2 and which provides means for likewise rotating the tail drum2 at the proper speed for efficient advancement of the cement materialstreated therein, depending upon the particular inclination of its axis.The upper or feed end I5 of the head drum I enters a housing I6communicating through a conduit I8 with a chimney or stack I1, a blowerI9 being provided for inducing a draft through the conduit I8. A Ferriswheel feeder 20 is suitably mounted on the housing I6 and is used tomeasure the entire amount of Vwet material admitted to the two drums,and dispenses a portion of this material against those chains located atthe lower or discharge end 22 of the head drum I and simultaneouslydispenses a further portion of this material directly into the head drumI through the feed end I5 thereof. The specific features of the novelFerris Wheel feeder 20, used with both the alternative preferredtwo-drum kiln and the unitary kiln, in practicing this invention, willbe considered in detail in later portions of the specification.

'I'he discharge or lower end 22 of the head drum enters an intermediatehousing 23 forming in effect a connecting gas passage between the taildrum 2 and the head drum I. The inlet or feed end 24 of the tail drum 2also enters the housing 23 and the lower portion of housing 23 is shownas providing a collector pocket 26 into which is discharged the driedmaterial leaving the head drum I, performing the drying function, thematerial thus being in dry condition and in proper condition foradmission to the tail drum said material.

2. The dried material kcollecting inthe collector y pocket 26 istransferred to a spout 30 and admitted into the feed end 24 of the taildrum 2 by means of an elevator 21 having elevating mechanism 28including buckets 1 andr driving 5 gear and pinion 29. The lower ordischarge end 25 of the tail drum 2 enters a firing hood 32 whichprovides a passage to a discharge bin 3| provided in the floor 3, formaterials completely treated in the kiln.

A fuel injection device 33 has a nozzle 2| enter` ing the ring hood 32and directed in approximate alinement with the axis of the tail drum 2,said `fuel injection device forming the means for burningfuel in thetail drum 2 resulting in the 15 hot combustion gases which move alongthe interior of the kiln or heating chamber in a direction opposite tothat of the advance of thematerial therethrough and in direct contactwith The hea`d drum I is provided with transverse, fiexible heattransferring members of metal as, for example, chains 34 which serve toprovide the desired increased amount of heat absorbing surfaces for theadherence and heating of the wet 25 raw material to be directly exposedto the hot gases of combustion coming from the tail drum 2. The chains34 immediately adjacent the point vof connection of the lhousing 23 andthe head drum I are protected 'through spraying 30 `upon them a portionof the wet raw material,

in the form of slurry, as indicated, in the manner nowto be explained. l

'I'he Ferris wheel feeder 20 comprises a main receptacle 35 having aside wall a portion of 35 which forms also one wall of an auxiliaryreceptacle or supply sump 40. The supply sump 4II is in communicationthrough an aperture 4I located in said common side wall with a hopper 42disposed within the main receptacle 35 and carried 40 by the said commonwall of the receptacles. 'I'his hopper 42 receives the wet raw materialpermitted to fall by gravity from the buckets 31 of the Ferris wheel 36,which is suitably carried by the other side wall of the main receptacle,as illus- 45 trated, and is rotated at the proper speed.v

The wet raw cement material or slurry, preferably of the highestworkable consistency to keep as low as possible the amount of' heat tobe exl pended in evaporating its water content while 50 within the drumI, is admitted into the main receptacle 35 through an inlet pipe 38. Theelevation of the raw cement materials in the main receptacle 35 isprimarily controlled by an outlet or overflow pipe 39 connecting intothe interior 55 of the main receptacle, at the desired elevation. Thesump 4U has a standpipe 43 therein, one branch 45 of which terminates inan end having a removable closure 46 provided for the insertion ofproper tools to clear the passage from the (i0 standpipe 43 to its mainbranch 44, shouldl this passage become clogged. The main branch 44serves as an inlet spout for the major portion of slurry admitteddirectly into the feed end I 5 of the head drum I in directionfcounterto the 65 flow of hot gas therethrough. The sump 40 further has a pipe48 communicating with the interior thereof adjacent its bottom, whichpipe aoaaoso of housing 23, and into the lower end of the head drum I inthe same direction as the gas flow, so that the spray rst negotiates thegases traveling through the housing 23 and subsequently directlyengages` those chains located nearest the discharge end of the headdrum, for the purpose of coating these chains with the proper amount ofwet slurry, particularly on the sides thereof first engaged by the hotgases, to prevent their rapid deterioration by the hot combustin gasesleaving the housing 23, to which these chains are continuouslysubjected.

The function of the Ferris wheel feeder 20, is to handle all .the slurrywhich is ultimately introduced at the vdescribed places into the headdrum and thereby supply the entire feed to the kiln at a uniform rate ofiiow with constant* rotation of the Ferris wheel 36. The purpose of thehopper'42 is to receive the uniform flow of material, determined by thenumber of buckets on the Ferris wheel 36 and by the number ofrevolutions of the Ferris wheel 36, and

to feed the material uniformly through the opening 4I to the common sump40. The arrangement in the sump 40 is such that with a certain headprovided and maintained by the Ferris'.

wheel 36, the pump 41 will be able to supply a uniform portion of theslurry through the nozzle 50 onto the chains 34 at the lower end of thehead drum I. The corresponding head on the standpipe 43 will effect theintroduction of thel remaining portion of the slurry directly into thefeed end I5 of the head drum I.", The effect -of the tempered gases uponthe chains above these lower chains in the head drum I and beyond therange of the spray from nozzle 5l), is of little importance since theportion of the slurry admitted directly into the feed end I5 through thestandpipe 43, will permit these chains to engage and intermingle withadvancing wet slurry to keep them at the proper temperature. Theseactions simultaneously effect almost a complete drying of the advancingmaterial as the range of the spray from nozzle 50 is approached. Theaction of the drying zone is such that the slurry will be insubstantially dry condition as it leaves the head drum I, as abovedescribed.

Figure 4 illustrates the alternative application of the invention in aunitary kiln IOI having the defined burning and drying zones. The dryingzone of the unitary kiln IUI illustrated fragmentarily in this figure issimilarly provided with the chains 34 or other metallic heattransferring 'members for increasing the heating surface for this zonemay also be provided with the rings 6 and with the ring gear9contributing in the support and rotation respectively, of the unitarykiln. A portion of the slurry or other wet raw material may be dispensedinto the feed end of the kiln IIJI, by means of the inlet' spout 44 ofthe Ferris Wheel feeder illustrated in Figs. l, 2 and 3 and described inconnection with these figures.

In order to supply the desired portion of the wet raw material to thechains at the lower end of the drying zone, the pipe 49 connected to thedischarge of the pump 41 of Fig. 1 is connected with a nozzle 50|through the intermediary of a further pipe 49 `provided with connectionsabout to be described. For this purpose a pipe 6I may be extendedthrough the wall of kiln I-IJI adjacent its feed end, which pipe 6I maybe secured to said wall by means of a iianged member62. An axiallypositioned union 60 allows proper rotative movement of the pipe 6I withrespect to an end of the described interrupted pipe 49. Beyond theinterrupted pipe 49 the further pipe 49 is secured to the kiln IUI, and5 one of the ends of this further pipe 49 is connected by means ofaunion 63 with the outwardly projecting end of pipe 6I. The other end ofthe further pipe 49 is connected to the outward- 1y projecting end ofthe nozzle 50 I held by means 10 of another flanged member 62 fixedlywith respect tothe kiln IIJI, by means of another union 63. Thearrangement of the invention in the unitary kiln of Fig. 4 and themanner-in which the invention is practised therein should be clear l5when the arrangement is referred to Fig. 1 and to the detaileddescription of the operation of the kiln shown in this figure.

It should-be understood that it is not intended to limit the inventionto the constructions shown 20 and described for various modificationswithin they scope of the claims may occur" to persons skilled in theart.

It is claimed and desired to secure by Letters Patent:

l. A heater of the direct contact hot gas now type comprising meanstherein adjacent the material inlet end of said heater for increasingthe surface area of contact for the material, means vfor introducingcounter to the gas flow a portion of the material to be heated,'andmeans for introducing in the same direction as the gas ow anotherportion of the material to be heated.

2. A heater of the direct contact hot gas flow type comprising meanstherein adjacent the material inlet end of said heater for increasingthe surface area of contact for the material, means for producing a owpast said area increasing means of a major portion of the material to beheated counter to the gas iiow, and 40 means for producing a ow pastsaid areal increasing means in the same direction as the gas flow of aminor portion of the material to be treated.

3. In a rotary kiln having metallic members near its feed end andextending across the inner surface at said feed end, a supply forfurnishing wet material to said kiln, an adjustable feeder device forfeeding said supply with regulatable quantities of said Wet material,means for feeding a portion of said wet material to the feed end of thekiln and means for introducing a further portion of said wet materialdirectly on to those metallic members nearest the discharge end of thekiln, each of said means including a supply conduit and said conduitoriginating at different head levels from said supply.

4. In a rotary kiln having metallic members near its feed end andextending across the inner surface thereat, means for supplying wetmaterial to the feed end of the kiln, and means for `the introduction ofa further portion of said wet material at a point adjacent thosemetallic members nearest the discharge end of the kiln, both -of saidmeans connecting into a common sump and including conduits terminatingat different head levels therein, said sump being supplied withregulatable quantities of said material by an adjustable feeder device,one of said means further including a forcing means the operation ofwhich together with a given ldelivery of the feeder device determiningthe proportion of said material admitted to the kiln at the describedpoints.

5. A rotary kiln for the burning and drying of 76 raw cement materialintroduced as slurry, comprising a rotary head drum, means for rotatingsaid drum, a rotary tail drum, means for separately rotating said taildrum, means for introducing heat into said tail drum, means forintroducing slurry into said head drum at the inlet end thereof, thedrums being arranged and the arrangement cooperating with meanscommunieating with said drums whereby the advance of the material beingtreated in the drums is in a direction opposite from the travel of thehot gases through the drums, and slurry conveying means connecting aportion of the means communicating with the drums and the means forintroducing slurry into the head drum, for introducing a further portionof slurry into said head drum at the other end thereof, to provide anincreased heat recuperation within the kiln.

6. A rotary kiln for the burning and drying of raw cement materialintroduced as slurry, comprising a rotary head drum, means for rotatingsaid drum, flexible heat conducting members extending along and locatedtransversely within said head drum, a rotary tail drum, means forseparately rotating said tail drum, means for introducing heat into saidtail drum, means for introducing slurry into said head drum a"t theinlet end thereof, the drums being arranged and the arrangementcooperating with means communicating with said drums whereby the advanceof the materials being treated in the drums is in a direction oppositefrom the travel of the hot gases through the drums, and siun'y conveyingmeans'connecting a portion of the means communicating with the drums andthe means for introducing slurry into the head drum, for introducing afurther portion' of slurry into said head drum and against the membersat the other end thereof, to provide an increased heat recuperationwithin the kiln.

1. A rotary kiln for the burning and drying of raw cement materialintroduced as slurry,4 comprising a rotary head drum, exible heatconducting members extending along and located transversely within saidhead drum, means for rotating said drum, a rotary tail drum, means forseparately rotating said tail drum, means for introducing heat into saidtail drum at the discharge end thereof, means for introducingregulatable portions of slurry into the head drum at the inlet anddischarge ends thereof, means communicating with the drums and forming aconnecting passage for the travel of gases through the drums in adirection opposite from the passage of the material being treatedtherethrough, and means for conveying material discharged from the headdrum, to the tail drum. Y

8. A rotary kiln for the burning and drying of raw cement materialintroduced as slurry, comprising a rotary head drum, flexible heatconducting members extending along and located transversely within saidhead drum. means for rotating said drum,` a rotary tail drum, means forseparately rotating said tail drum, means for introducing heat into saidtail drum at the discharge end thereof, means for introducingregulatable portions of slurry into the head drum at the feed anddischarge ends thereof, means communicating with the drums and forming aconnecting passage for the travel of the gases through the drums in adirection opposite from the po of the material being treated through thedrums, means for conveying material discharged from the head'drum to thetail drum, the means for introducing slurry at the discharge end of thehead drum including a nozzle effecting a spraying of wet material withinsaid passage thus subjecting the moving gases thereat to temperaturereductions and a spraying into the head drum and onto the flexiblemembers therein located 5 and extended thereaiong by reason of theirbeing within the range of cooling and coating influence of the slurryspray projected from said nozzle.

9. In combination, a pair of segregated, rotary drums for heat treatingof wet material passed progressively and successively through the rotarydrums, means providing heat liberating gases passing through the drumsin a direction opposite from that of the material, means for regulatingthe entire feed to the drums, said means comprising a bucket wheelsubmerged in a container having provision for maintaining asubstantially constant head of wet material therein, the buckets of saidwheel emptying into a container provided with a ow passage to a sump,and separate conduits communicating at different points with said sumpand directed into the ends of one of said drums.

10. In combination, a pair of segregated, rotary drums for drying andburning of wet cement raw material passed progressively and successivelythrough the drums, means providing heat liberating gases passing throughthe drums in a direction opposite from that of the material, one of saiddrums being provided with heat conducting flexible members extendingalong and located transversely of the inner surface thereof and locatedintermediate the two ends thereof, means for regulating the entire feedto the drums, said means comprising a Ferris wheel feeder having adelivery sump and separate conduits communicang with the sump atdifferent head levels and delivering to the ends oi.' the said drumprovided with the flexible members, a pump being provided in the conduitleading to the discharge end 40 of the drum provided with the flexiblemembers to provide a positive flowy of material through its conduit, theother conduit removing the excess material over that necessary to besupplied to the discharge end of the drum provided with the fiexiblemembers, to carry out the temperature reductions of the gases andcoating of the flexible members. for heat protection purposes asdescribed, to the feed end of said drum provided with the exiblemembers.

11. A direct contact heater, comprising a chamber, means for owing hot`gas through said chamber, heat absorbing elements disposed within saidchamber, means for flowing material to be heated through said chamber incontact with said heat absorbing elements, and `means for pro- Jecting aportion of the material to be heated directly upon the heat absorbingelements first contacted by the intlowing hot gas in direction toimpinge upon the sides of said elements irst en- 00 gaged by said gas toprotect said elements from destruction by said hot gas.

12. A rotary kiln, comprising a rotatable casing, heat transferringmeans disposed within said casing, means for owing hot gases throughsaid casing, means for flowing wet material to be heated through saidcasing in direction counter to the gas flow, and means for spraying aportion of said wet material to be heated in the direction of said gasflow on to the heat transferring means first contacted by the incominghot gases to protect said means from being destroyed by said hot gases.

RAY C. NEWHOUBE. 7l

, CERTIFICATE o F CORRECTION.

'Patent No. 2,027,059. January 7, 1936.

` RAY o. NEwHoUs-E.

" 4It is hereby certified that error appears in the printedspecification of the above Anumbered patent requiring correction asfollows: Page E, secorlld column, line 56, p claim 3, for "conduit" readconduits; page 4, second column,

line 35, claim 10, for "Ferris" readwferris' and that the said LettersPatent should be read. with these oorrectiors 'therein that the same mayconform to the record of the case in the Patent Office.

Signed. and sealed this 11th day of February, A.' D. 1936.

,Leslie Frazer (Seal) Acting Commissioner of Patents.

